Quiz Questions

Question 1 1 Marks

What is the use of anemometer?

A

Check water flow

B

Measure air flow

C

Produce current

D

Measure voltage

Question 2 1 Marks

Which medium is used to extinguish Class - A fire?

A

CO2

B

Foam

C

Water

D

Dry powder

Question 3 1 Marks

Which type of defrosting method is used in frost free refrigerator?

A

Hot water defrosting

B

Manual defrosting

C

Hot gas defrosting

D

Electric defrosting

Question 4 1 Marks

Which gas is used to flush out the coils of air cooled condenser?

A

Dry nitrogen

B

Pure dry air

C

Oxygen

D

kaksr

Question 5 1 Marks

What is the revolving part of induction motor?

A

Stator

B

Rotor

C

Relay

D

Winding

Question 6 1 Marks

Which fan is used in condensing unit of ductable split air conditioner?

A

Forward curved fan

B

Centrifugal fan

C

Propeller fan

D

Radial fan

Question 7 1 Marks

Which device meters the amount of refrigerant entering the evaporator in window AC?

A

Accumulator

B

Capillary tube

C

Heat exchanger

D

Finned tube condenser

Question 8 1 Marks

What is the advantage of universal colour coding of refrigerant cylinders?

A

Easy to identify

B

Make good appearance

C

Prevent corrosion on cylinder

D

Provide extra strength to cylinder

Question 9 1 Marks

Where the dehydrator is installed in a refrigeration system?

A

Discharge line

B

Capillary line

C

Suction line

D

Liquid line

Question 10 1 Marks

Which thermodynamic process the temperature is kept constant?

A

Isobaric process

B

Isothermal process

C

Constant volume process

D

Constant pressure process

Question 11 1 Marks

Which gas is used for flushing blocked capillary tube?

A

Moist air

B

Hydrogen

C

Dry nitrogen

D

Aqua ammonia

Question 12 1 Marks

How many parameters are needed to locate all properties of moist air in psychrometric chart?

A

One

B

Two

C

Four

D

Three

Question 13 1 Marks

Which is the mounting location of evaporator in ductable split unit?

A

Floor mounting

B

Wall mounting

C

Ceiling mounting

D

Roof mounting

Question 14 1 Marks

Which two tubes act as heat exchanger in a refrigerator?

A

Suction and charging tube

B

Discharge and suction tube

C

Capillary and suction tube

D

Discharge and capillary tube

Question 15 1 Marks

What is the absolute pressure of gas in a cylinder, if gauge reads 135.3 p.s.i?

A

130 p.s.i.a

B

140 p.s.i.a

C

150 p.s.i.a

D

160 p.s.i.a

Question 16 1 Marks

What is the position of knob selected in thermostat to check its working condition in package AC?

A

Fan only

B

Low cool

C

High cool

D

Medium cool

Question 17 1 Marks

Which causes the filter drier to become cold in chiller AC plant?

A

Over charge

B

Under charge

C

High condensing pressure

D

Partial blocking of filter drier

Question 18 1 Marks

Which gas is used for pressurising and testing leakage of RAC system?

A

O2

B

N2

C

O3

D

SO2

Question 19 1 Marks

Which instrument measures the humidity of air?

A

Barometer

B

Manometer

C

Hygrometer

D

Hydrometer

Question 20 1 Marks

Which material is used to make electrode holder for welding?

A

Steel

B

Cast iron

C

Cast iron

D

Copper alloy

Question 21 1 Marks

What is the colour of acetylene hose pipe in oxy - acetylene welding set?

A

Maroon

B

Green

C

Black

D

Red

Question 22 1 Marks

What is the function of starting capacitor in CSIR motor?

A

Gives initial torque

B

Gives running torque

C

Corrects power factor

D

Improves energy efficiency

Question 23 1 Marks

What is the reason for swash plate compressor failure in car AC?

A

Oil level is low

B

Oil level is medium

C

Thermostat not working

D

Refrigerant charge normal

Question 24 1 Marks

What is the reason for poor compression?

A

Less clearance volume

B

Scratches on the piston surface

C

Lapped valve plate and reed seat

D

Good lubrication on the moving parts

Question 25 1 Marks

What is the cooling capacity for 1.5 Ton of ductable split air conditioner?

A

3500 Kcal/hr

B

4000 Kcal/hr

C

4500 Kcal/hr

D

5000 Kcal/hr

Question 26 1 Marks

Which sheet is used to check the tigtness of door gasket of a refrigerator?

A

Rubber

B

Plastic

C

Copper

D

Zinc

Question 27 1 Marks

What is the equivalent of one microfarad in farad?

A

10-3 farad

B

10-6 farad

C

10-9 farad

D

10-12 farad

Question 28 1 Marks

What is the method of converting AC to DC
power supply with two diodes and a step down
transformer?

A

Bridge rectifier

B

Full wave rectifier

C

Half wave rectifier

D

Medium wave rectifier

Question 29 1 Marks

Why the glass wool insulation is avoided in ducts?

A

Less strength

B

High conductivity

C

Not resistant to water

D

Allows vapour transmission

Question 30 1 Marks

How the space between the false ceiling and the building main ceiling is used in handling of air in central AC plant?

A

Exhaust duct

B

Fresh air duct

C

Return air duct

D

Supply air duct

Question 31 1 Marks

How the difference between the
synchronous speed and the actual rotor speed is
specified?

A

Lead

B

Lag

C

Slip

D

Trip

Question 32 1 Marks

What is the effect on system performance if the AC system is at undercharged condition?

A

Poor cooling

B

Excess cooling

C

Compressor over loading

D

Compressor trips by HP cut out

Question 33 1 Marks

What is the effect on defective thermostat sensor in split AC?

A

Unit consumes less power

B

Increases super heat

C

AC unit runs continuously

D

Relay malfunctions

Question 34 1 Marks

How pressure drop is achieved in capillary tube of refrigeration cycle?

A

The friction between refrigerant and tube

B

The friction between refrigerant and oil

C

The friction between piston and cylinder

D

The friction between belt and pulley

Question 35 1 Marks

What is the equivalent of 1 mm of Hg in
terms of microns?

A

500

B

1000

C

1500

D

2000

Question 36 1 Marks

Which type of evaporator is used in frost free refrigerator?

A

Plate type

B

Wire mesh

C

Finned tube

D

Shell and tube

Question 37 1 Marks

Which version of motors are used in ductless multisplit system?

A

Bioptional drive

B

Trioptional drive

C

Variable frequency drive

D

Constant frequency drive

Question 38 1 Marks

Which component belongs to indoor unit of split AC?

A

Compressor

B

Condenser

C

Evaporator

D

Drier

Question 39 1 Marks

1 Which control device is used to maintain the room air temperature?

A

OLP

B

Relay

C

Thermostat

D

Selector switch

Question 40 1 Marks

What is the effect if the refrigeration system is started before chilled water pump?

A

No cooling

B

Water warms in chillier

C

Water freezes in chillier

D

Excess of heat transfer

Question 41 1 Marks

Which component is connected in series with bimetal thermo in a frost free refrigerator?

A

Blower

B

Door switch

C

Cabinet bulb

D

Defrost heater

Question 42 1 Marks

Which part of a central AC system cannot be repaired after pump down operation?

A

Condenser

B

Evaporator

C

Liquid receiver

D

Expansion device

Question 43 1 Marks

Which type of evaporator is used in house hold refrigerator?

A

Plate evaporator

B

Tube in tube evaporator

C

Shell and coil evaporator

D

Shell and tube evaporator

Question 44 1 Marks

What is the category of R 290 refrigerant?

A

Halocarbons

B

Azeotropes

C

Hydrocarbons

D

Organic compounds

Question 45 1 Marks

What is the cause of reduced supply air throw though air filter is clean in window AC?

A

No frost in the evaporator

B

Frost accumulated in the evaporator

C

Dust accumulated in the condenser

D

No dust accumulated in the evaporator

Question 46 1 Marks

What is the advantage of electrically interlocked circuit for motors and pumps in a chiller plant?

A

Start the loads non sequentially

B

Start the loads when not needed

C

Stop the loads when not required

D

Start and stop the loads sequentially

Question 47 1 Marks

Why the top of dome is hot in a scroll compressor?

A

Discharge plenum is at top

B

Suction super heat is less

C

Suction gas not cooled

D

Undercharged system

Question 48 1 Marks

What is the effect of longer suction and liquid piping in AC?

A

No pressure rise

B

More pressure drop

C

Less pressure drop

D

Medium pressure rise

Question 49 1 Marks

What is the cause of high condensing pressure in water cooled condenser?

A

Lack of lubrication

B

Damage condenser fan

C

Low load on evaporator

D

Defective cooling water pump

Question 50 1 Marks

Which part connects the piston with small end of connecting rod in a reciprocating compressor?

A

Piston pin

B

Piston bolt

C

Piston rings

D

Piston sleeve

Question 51 1 Marks

Which set of components are used in FCU?

A

Air filter, blower, condenser

B

Compressor, fan, condenser

C

Air filter, cooling coil, blower motor

D

Cooling coil, condenser, fan motor

Question 52 1 Marks

Which part of the refrigerator cools the liquid refrigerant in capillary tube?

A

Discharge line

B

Suction line

C

Condenser

D

Evaporator

Question 53 1 Marks

What is the formula to find out the
synchronous speed of induction motor?

A

Ns=(150P/f)

B

Ns=(120f/P)

C

Ns=(150f/P)

D

Ns=(120P/f)

Question 54 1 Marks

What is the advantage of using flux in brazing?

A

Over heating

B

Melting tubes

C

Prevent Oxidation

D

Chemical reaction

Question 55 1 Marks

What is the preventive maintenance of cooling tower sump?

A

Remove sludge

B

Flush with water

C

Add HCL to water

D

Add bleaching powder

Question 56 1 Marks

What is the function of starting capacitor in CSIR motor?

A

Gives initial torque

B

Gives running torque

C

Corrects power factor

D

Improves energy efficiency

Question 57 1 Marks

What is the advantage of using capillary tube as an expansion device?

A

Temperature balancing is easy

B

Pressure balancing is easy

C

Volume balancing is easy

D

Complicate design

Question 58 1 Marks

Which horizontal distance is preferred between indoor and outdoor units in ductable split AC installation?

A

15 meters

B

12 meters

C

20 meters

D

25 meters

Question 59 1 Marks

What is the unit of heat in M.K.S system?

A

B.T.U (British thermal unit)

B

K.Cal (Kilo Calorie)

C

KV (Kilo Volt)

D

K.W (Kilo Watt)

Question 60 1 Marks

What is the periodical checking for blower belt in package AC?

A

Daily

B

Yearly

C

Weekly

D

Monthly

Question 61 1 Marks

How the refrigerants are classified based on heat absorption by latent and sensible heat?

A

Primary and secondary

B

Organic and inorganic

C

Zeotropic and azeotropic

D

Halocarbons and hydrocarbons

Question 62 1 Marks

Which valve is used to release the non condensable gases from AC plant?

A

Purge valve

B

Check valve

C

Service valve

D

Solenoid valve

Question 63 1 Marks

Which application uses the digital
ICs?

A

Amplifier

B

Logic gates

C

Tuned circuits

D

Voltage regulator

Question 64 1 Marks

Which winding has more inductance in refrigerator compressor motor?

A

Run

B

Start

C

Common

D

Start and common

Question 65 1 Marks

What is the velocity pressure of air in a duct if the total pressure and static pressure are known?

A

Sum of static and total pressures

B

Sum of dynamic and total pressures

C

Difference in static and total pressures

D

Difference in dynamic and total pressures

Question 66 1 Marks

What is the wet bulb temperature of air if dry bulb temperature is 35 Degree Centigrade and wet bulb depression is 4 Degree Centigrade?

A

30 Degree Centigrade

B

31 Degree Centigrade

C

32 Degree Centigrade

D

33 Degree Centigrade

Question 67 1 Marks

What is the remedy for no lubrication even if the sight glass shows proper oil level?

A

Replace oil pump

B

Add oil to crankcase

C

Replace oil pressure gauge

D

Replace oil pressure cut out

Question 68 1 Marks

Which is connected in series with start capacior in motor circuit?

A

Starting winding

B

Common terminal

C

Running Terminal

D

Running winding

Question 69 1 Marks

What is the remedy for scaled up water tubes of water cooled condenser?

A

Clean the surface

B

Wipe the condenser fins

C

Descale the condenser tubes

D

Wash the condenser with soap water

Question 70 1 Marks

What is the advantage of ductable air conditioner over window air conditioner?

A

Higher cost

B

Noisy operation

C

Silent operation

D

Needs more space

Question 71 1 Marks

Which extinguishes the fire on electrical equipment?

A

Oil

B

Foam

C

Water

D

Halon

Question 72 1 Marks

How much cut out point is set in high pressure control in package AC using R-22?

A

12 kg/cm2

B

15 kg/cm2

C

17 kg/cm2

D

20 kg/cm2

Question 73 1 Marks

What is the purpose of using goggles during chipping the slag from weld bead?

A

To protect eyes

B

To protect hand

C

To protect leg

D

To protect head

Question 74 1 Marks

What is the advantage of periodical cleaning of air filter?

A

Decrease the volume of air handling

B

Increase the speed of fan motor

C

Decrease the cooling capacity

D

Increase the cooling capacity

Question 75 1 Marks

Which fan motor speed is used with outdoor unit in split AC?

A

Single speed

B

Double speed

C

Triple speed

D

Five speed

Question 76 1 Marks

Which cooling medium is used to cool the motor of a hermetic reciprocating compressor in AC?

A

Discharge vapour

B

Liquid refrigerant

C

Suction vapour

D

Water

Question 77 1 Marks

What is the ozone depleting potential of R 134a Refrigerant?

A

0

B

1

C

2

D

3

Question 78 1 Marks

Which type of expansion device is used in frost free refrigerator?

A

Float valve

B

Capillary tube

C

Automatic expansion valve

D

Thermostatic expansion valve

Question 79 1 Marks

Which is circulated in VRV system for cooling cycle?

A

Water

B

Cooled air

C

Cooled brine

D

Liquid refrigerant

Question 80 1 Marks

What is the equivalent of one micron in millimeter?

A

0.0001 mm

B

0.001 mm

C

0.01 mm

D

0.1 mm

Question 81 1 Marks

Why the temperatures of inlet and outlet water in shell and tube condenser are recorded in log sheet?

A

Study about the plant

B

Judge quality of water

C

Checking the hardness of water

D

Fix descaling time for condenser

Question 82 1 Marks

Which is scheduled for yearly maintenance in package AC?

A

Wash the air filter

B

Tighten the blower belt

C

Clean the cooling tower

D

Tighten the pump gland nut

Question 83 1 Marks

What is the pH level of water used for final
rinsing of condenser tubes after descaling?

A

4 to 4.5

B

7 to 7.5

C

10 to 12

D

9 to 10.5

Question 84 1 Marks

What is the effect of sensing higher
temperature by thermistor NTC?

A

Resistance increases

B

Resistance decreases

C

Resistance becomes zero

D

Resistance becomes infinity

Question 85 1 Marks

How the level of heat in a substance is
expressed?

A

Micron

B

Pressure

C

Humidity

D

Temperature

Question 86 1 Marks

Which device controls the moisture in AC room air?

A

Humidistat

B

Hydrometer

C

Hygrometer

D

Anemometer

Question 87 1 Marks

Where the manually defrosted water is stored in refrigerator?

A

Tray on top of the compressor

B

Bottom of the evaporator

C

Bottom of the condenser

D

Top of the freezer

Question 88 1 Marks

What is the diameter of liquid line used with 5 TR if the suction line is 7/8 OD by up flow?

A

1/2? OD

B

5/16 ? OD

C

3/8 ? OD

D

3/4 ?OD

Question 89 1 Marks

Which parameter of power supply reduces the starting current in VFD motor?

A

Decreased power factor

B

Increased supply voltage

C

Lower frequency operation

D

Decreased resistance mode

Question 90 1 Marks

Which is a positive displacement
compressor?

A

Centrifugal compressor

B

Scroll compressor

C

Water pump

D

Oil pump

Question 91 1 Marks

Which type of fan blade is used with indoor unit?

A

Guide vane

B

Blower

C

Axial

D

Vane|

Question 92 1 Marks

What is the cause for noisy fan motor in outdoor unit of split AC?

A

Bearing worn out

B

Motor Burnt

C

Shaft struck

D

Blade bent

Question 93 1 Marks

Which refrigerant blend is highly flammable?

A

HCFC

B

HFC

C

CFC

D

HC

Question 94 1 Marks

Which method is used to connect the swaged joint in copper tubes?

A

TIG welding

B

Silver brazing

C

Lead soldering

D

Fusion welding

Question 95 1 Marks

Which is the mounting location of evaporator in ductable split unit?

A

Floor mounting

B

Wall mounting

C

Ceiling mounting

D

Roof mounting

Question 96 1 Marks

What is the least count of a metric micrometer?

A

0.1 mm

B

0.01 mm

C

0.001 mm

D

000.1 mm

Question 97 1 Marks

Which type of drier filter is suitable for HFC refrigerants?

A

Molecular sieve type

B

Activated alumina

C

Activated carbon

D

Silica gel

Question 98 1 Marks

Which type of processor control is used for safety in package air conditioner?

A

Electric

B

Mechanic

C

Electronic

D

Pneumatic

Question 99 1 Marks

Which safety control is actuated by excess of heat /current in package AC?

A

Selector switch

B

Over load relay

C

Water flow switch

D

High pressure cut-out

Question 100 1 Marks

Which joint is made in either single or multi - strand conductors?

A

Rat tail joint

B

Scarfed joint

C

Britannia joint

D

Western union joint

What is the use of anemometer?

Which medium is used to extinguish Class - A fire?

Which type of defrosting method is used in frost free refrigerator?

Which gas is used to flush out the coils of air cooled condenser?

What is the revolving part of induction motor?

Which fan is used in condensing unit of ductable split air conditioner?

Which device meters the amount of refrigerant entering the evaporator in window AC?

What is the advantage of universal colour coding of refrigerant cylinders?

Where the dehydrator is installed in a refrigeration system?

Which thermodynamic process the temperature is kept constant?

Which gas is used for flushing blocked capillary tube?

How many parameters are needed to locate all properties of moist air in psychrometric chart?

Which is the mounting location of evaporator in ductable split unit?

Which two tubes act as heat exchanger in a refrigerator?

What is the absolute pressure of gas in a cylinder, if gauge reads 135.3 p.s.i?

What is the position of knob selected in thermostat to check its working condition in package AC?

Which causes the filter drier to become cold in chiller AC plant?

Which gas is used for pressurising and testing leakage of RAC system?

Which instrument measures the humidity of air?

Which material is used to make electrode holder for welding?

What is the colour of acetylene hose pipe in oxy - acetylene welding set?

What is the function of starting capacitor in CSIR motor?

What is the reason for swash plate compressor failure in car AC?

What is the reason for poor compression?

What is the cooling capacity for 1.5 Ton of ductable split air conditioner?

Which sheet is used to check the tigtness of door gasket of a refrigerator?

What is the equivalent of one microfarad in farad?

What is the method of converting AC to DC power supply with two diodes and a step down transformer?

Why the glass wool insulation is avoided in ducts?

How the space between the false ceiling and the building main ceiling is used in handling of air in central AC plant?

How the difference between the synchronous speed and the actual rotor speed is specified?

What is the effect on system performance if the AC system is at undercharged condition?

What is the effect on defective thermostat sensor in split AC?

How pressure drop is achieved in capillary tube of refrigeration cycle?

What is the equivalent of 1 mm of Hg in terms of microns?

Which type of evaporator is used in frost free refrigerator?

Which version of motors are used in ductless multisplit system?

Which component belongs to indoor unit of split AC?

1 Which control device is used to maintain the room air temperature?

What is the effect if the refrigeration system is started before chilled water pump?

Which component is connected in series with bimetal thermo in a frost free refrigerator?

Which part of a central AC system cannot be repaired after pump down operation?

Which type of evaporator is used in house hold refrigerator?

What is the category of R 290 refrigerant?

What is the cause of reduced supply air throw though air filter is clean in window AC?

What is the advantage of electrically interlocked circuit for motors and pumps in a chiller plant?

Why the top of dome is hot in a scroll compressor?

What is the effect of longer suction and liquid piping in AC?

What is the cause of high condensing pressure in water cooled condenser?

Which part connects the piston with small end of connecting rod in a reciprocating compressor?

Which set of components are used in FCU?

Which part of the refrigerator cools the liquid refrigerant in capillary tube?

What is the formula to find out the synchronous speed of induction motor?

What is the advantage of using flux in brazing?

What is the preventive maintenance of cooling tower sump?

What is the function of starting capacitor in CSIR motor?

What is the advantage of using capillary tube as an expansion device?

Which horizontal distance is preferred between indoor and outdoor units in ductable split AC installation?

What is the unit of heat in M.K.S system?

What is the periodical checking for blower belt in package AC?

How the refrigerants are classified based on heat absorption by latent and sensible heat?

Which valve is used to release the non condensable gases from AC plant?

Which application uses the digital ICs?

Which winding has more inductance in refrigerator compressor motor?

What is the velocity pressure of air in a duct if the total pressure and static pressure are known?

What is the wet bulb temperature of air if dry bulb temperature is 35 Degree Centigrade and wet bulb depression is 4 Degree Centigrade?

What is the remedy for no lubrication even if the sight glass shows proper oil level?

Which is connected in series with start capacior in motor circuit?

What is the remedy for scaled up water tubes of water cooled condenser?

What is the advantage of ductable air conditioner over window air conditioner?

Which extinguishes the fire on electrical equipment?

How much cut out point is set in high pressure control in package AC using R-22?

What is the purpose of using goggles during chipping the slag from weld bead?

What is the advantage of periodical cleaning of air filter?

Which fan motor speed is used with outdoor unit in split AC?

Which cooling medium is used to cool the motor of a hermetic reciprocating compressor in AC?

What is the ozone depleting potential of R 134a Refrigerant?

Which type of expansion device is used in frost free refrigerator?

Which is circulated in VRV system for cooling cycle?

What is the method of converting AC to DC
power supply with two diodes and a step down
transformer?

How the difference between the
synchronous speed and the actual rotor speed is
specified?

What is the equivalent of 1 mm of Hg in
terms of microns?

What is the formula to find out the
synchronous speed of induction motor?

Which application uses the digital
ICs?

What is the pH level of water used for final
rinsing of condenser tubes after descaling?

What is the effect of sensing higher
temperature by thermistor NTC?

How the level of heat in a substance is
expressed?

Which is a positive displacement
compressor?